CN115296501B - Double-stator single-rotor permanent magnet synchronous motor - Google Patents

Abstract

The invention provides a double-stator single-rotor permanent magnet synchronous motor, relates to the technical field of motors, aims to optimize the motor structure to a certain extent, fully utilizes the internal cavity of the motor and improves the torque density of the motor. The invention provides a double-stator single-rotor permanent magnet synchronous motor, which comprises an outer motor, a rotor assembly and an inner motor; the rotor assembly comprises a plurality of outer rotor pole shoes and a plurality of inner rotor pole shoes, a cavity is formed in the outer motor, the inner motor and the rotor assembly are both arranged in the cavity, and the rotor assembly is positioned between the inner motor and the outer motor; the outer rotor pole shoes are uniformly distributed along the circumferential direction of the outer motor, the inner rotor pole shoes are uniformly distributed along the circumferential direction of the inner motor, and gaps are formed between the outer rotor pole shoes and the outer motor and between the inner rotor pole shoes and the inner motor.

Description

Double stator single rotor permanent magnet synchronous motor

Technical Field

The present invention relates to the technical field of motors, and in particular to a double-stator single-rotor permanent magnet synchronous motor.

Background Art

As a highly efficient transmission equipment, belt conveyors are widely used in coal mining conditions. Such conditions place high demands on the drive motors of belt conveyors. Traditional belt conveyors mostly use asynchronous motors and reducers as a driving method. Although this type of driving technology is relatively mature, it has disadvantages such as high energy consumption, high maintenance, and large size. Therefore, this type of driving method can no longer meet the needs of industrial and mining enterprises to significantly improve the performance of belt conveyors. Therefore, it is necessary to use high-torque density and high-efficiency rare earth permanent magnet motors to achieve low-speed direct drive of belt conveyors.

However, since most permanent magnet motors have a large diameter and a large internal cavity space, if the torque density of the motor needs to be increased, the size of the motor will increase, which is not conducive to the miniaturization of the motor and limits the use environment of the motor.

Therefore, there is an urgent need to provide a dual-stator single-rotor permanent magnet synchronous motor to solve the problems existing in the prior art to a certain extent.

Summary of the invention

The purpose of the present invention is to provide a dual-stator single-rotor permanent magnet synchronous motor, so as to optimize the motor structure to a certain extent, make full use of the internal cavity of the motor, and improve the torque density of the motor.

The present invention provides a dual-stator single-rotor permanent magnet synchronous motor, comprising an outer motor, a rotor assembly and an inner motor; the rotor assembly comprises a plurality of outer rotor pole shoes and a plurality of inner rotor pole shoes, a cavity is formed inside the outer motor, the inner motor and the rotor assembly are both arranged in the cavity, and the rotor assembly is located between the inner motor and the outer motor; the plurality of outer rotor pole shoes are evenly arranged along the circumference of the outer motor, the plurality of inner rotor pole shoes are evenly arranged along the circumference of the inner motor, and gaps are formed between the outer rotor pole shoes and the outer motor, and between the inner rotor pole shoes and the inner motor.

Wherein, the rotor assembly further includes a magnetic isolation ring, and the magnetic isolation ring is located between the outer rotor pole shoe and the inner rotor pole shoe.

Specifically, a plurality of first embedded portions are formed on the side of the magnetic isolation ring facing the outer rotor pole shoe, and the plurality of first embedded portions are evenly distributed along the circumference of the magnetic isolation ring; a first matching portion is formed at the position of the outer rotor pole shoe corresponding to the first embedded portion, and the first matching portion matches with the first embedded portion to connect the outer rotor pole shoe with the magnetic isolation ring.

Furthermore, a plurality of second embedded portions are formed on the side of the magnetic isolation ring facing the inner rotor pole shoe, and the plurality of second embedded portions are evenly distributed along the circumference of the magnetic isolation ring; a second matching portion is formed at the position of the inner rotor pole shoe corresponding to the second embedded portion, and the second matching portion matches with the second embedded portion to connect the inner rotor pole shoe with the magnetic isolation ring.

Furthermore, the first matching portion and the second matching portion are both in a dovetail convex groove structure, and the first embedded portion and the second embedded portion are both in a dovetail concave groove structure.

Furthermore, the number of the first embedded parts and the number of the second embedded parts are the same, and the axes of the adjacent first embedded parts and the axes of the adjacent second embedded parts are arranged at an angle.

Among them, a plurality of first air magnetic barriers are formed on the outer rotor pole shoe, and the plurality of first air magnetic barriers are symmetrically arranged along the axis of the outer rotor pole shoe; a plurality of second air magnetic barriers are formed on the inner rotor pole shoe, and the plurality of second air magnetic barriers are symmetrically arranged along the axis of the inner rotor pole shoe; the plurality of first air magnetic barriers and the plurality of second air magnetic barriers are all filled with resin material.

Specifically, the outer rotor pole shoe and the inner rotor pole shoe are both formed by stacking a plurality of silicon steel sheets in sequence, the first air magnetic barrier and the second air magnetic barrier are both formed by cutting, and the ratio of the thickness of the first air magnetic barrier to the thickness of the outer rotor pole shoe and the ratio of the thickness of the second air magnetic barrier to the thickness of the inner rotor pole shoe are both 1:3.5.

Furthermore, permanent magnets are provided between adjacent outer rotor pole shoes and adjacent inner rotor pole shoes.

Furthermore, the outer motor includes an outer stator core and a first winding, and the inner motor includes an inner stator core and a second winding; a plurality of first bearing grooves are formed on the inner ring wall of the outer stator core, and the plurality of first bearing grooves are evenly spaced along the circumference of the inner ring wall of the outer stator core, and the axes of the first bearing grooves extend along the radial direction of the outer stator core, and the two long sides of the first winding are respectively arranged in two adjacent first bearing grooves; a plurality of second bearing grooves are formed on the outer ring wall of the inner stator core, and the plurality of second bearing grooves are evenly spaced along the circumference of the outer ring wall of the inner stator core, and the axes of the second bearing grooves extend along the radial direction of the inner stator core, and the two long sides of the second winding are respectively arranged in two different second bearing grooves.

Compared with the prior art, the dual-stator single-rotor permanent magnet synchronous motor provided by the present invention has the following advantages:

The dual-stator single-rotor permanent magnet synchronous motor provided by the present invention comprises an outer motor, a rotor assembly and an inner motor; the rotor assembly comprises a plurality of outer rotor pole shoes and a plurality of inner rotor pole shoes, a cavity is formed inside the outer motor, the inner motor and the rotor assembly are both arranged in the cavity, and the rotor assembly is located between the inner motor and the outer motor; the plurality of outer rotor pole shoes are evenly arranged along the circumference of the outer motor, the plurality of inner rotor pole shoes are evenly arranged along the circumference of the inner motor, and gaps are formed between the outer rotor pole shoes and the outer motor, and between the inner rotor pole shoes and the inner motor.

From this analysis, it can be seen that by arranging the inner motor and the rotor assembly in the cavity formed by the outer motor, the rotor assembly is located between the inner motor and the outer motor, thereby fully utilizing the cavity formed by the outer motor, and thus, without changing the overall size and volume of the motor, the torque density of the motor can be improved to a certain extent, and the overall performance of the motor can be improved.

Furthermore, since the rotor assembly in the present application includes an inner rotor pole shoe and an outer rotor pole shoe, and a gap is formed between the inner rotor pole shoe and the inner motor, and between the outer rotor pole shoe and the outer motor, the rotor assembly in the present application can be matched with the inner motor alone or with the outer motor alone, thereby enabling the dual-stator single-rotor permanent magnet synchronous motor provided in the present application to have three fixed output power modes.

When the working condition is light load, power output can be achieved only by supplying power to the inner motor; when the working condition is between light load and heavy load, power output can be achieved only by supplying power to the outer motor; when the working condition is heavy load, it is necessary to connect the inner motor and the outer motor in series and supply power to realize the joint action of the inner motor and the outer motor to achieve maximum power output to adapt to heavy load conditions.

Since the motor provided by the present application fully utilizes the internal space of the outer motor, it can improve the torque density and efficiency of the motor while ensuring that the volume remains unchanged. Moreover, through three different power outputs, it can not only better adapt to different working conditions, but also, when one of the inner motor and the outer motor fails, power can still be supplied for a certain period of time through the other structure, thereby improving the fault-tolerant operation capability of the motor to a certain extent.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic structural diagram of a dual-stator single-rotor permanent magnet synchronous motor provided by an embodiment of the present invention;

FIG2 is a schematic structural diagram of a spacer magnetic ring in a dual-stator single-rotor permanent magnet synchronous motor provided by an embodiment of the present invention;

3 is a schematic structural diagram of the relative positions of the outer rotor pole shoes and the inner rotor pole shoes in the dual-stator single-rotor permanent magnet synchronous motor provided by an embodiment of the present invention.

In the figure: 1-external motor; 101-external stator core; 102-first winding; 2-internal motor; 201-inner stator core; 202-second winding; 3-external rotor pole shoe; 301-first air magnetic barrier; 302-first matching part; 4-inner rotor pole shoe; 401-second air magnetic barrier; 402-second matching part; 5-permanent magnet; 6-magnetic isolation ring; 601-first embedded part; 602-second embedded part.

DETAILED DESCRIPTION

To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more items.

For ease of description, spatial relative terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the drawings. Such spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings.

The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and/or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and/or their combinations.

Variations in the shapes shown in the drawings may occur due to manufacturing techniques and/or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application. In addition, the technical solutions between the various embodiments may be combined with each other, but must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present application.

As shown in Figure 1, the present invention provides a dual-stator single-rotor permanent magnet synchronous motor, including an outer motor 1, a rotor assembly and an inner motor 2; the rotor assembly includes a plurality of outer rotor pole shoes 3 and a plurality of inner rotor pole shoes 4, a cavity is formed inside the outer motor 1, the inner motor 2 and the rotor assembly are both arranged in the cavity, and the rotor assembly is located between the inner motor 2 and the outer motor 1; the plurality of outer rotor pole shoes 3 are evenly arranged along the circumference of the outer motor 1, the plurality of inner rotor pole shoes 4 are evenly arranged along the circumference of the inner motor 2, and gaps are formed between the outer rotor pole shoes 3 and the outer motor 1, and between the inner rotor pole shoes 4 and the inner motor 2.

Compared with the prior art, the dual-stator single-rotor permanent magnet synchronous motor provided by the present invention has the following advantages:

The dual-stator single-rotor permanent magnet synchronous motor provided by the present invention arranges the inner motor 2 and the rotor assembly in the cavity formed by the outer motor 1, so that the rotor assembly is located between the inner motor 2 and the outer motor 1, thereby fully utilizing the cavity formed by the outer motor 1, and further, without changing the overall size and volume of the motor, the torque density of the motor can be improved to a certain extent, and the overall performance of the motor can be improved.

Furthermore, since the rotor assembly in the present application includes an inner rotor pole shoe 4 and an outer rotor pole shoe 3, and a gap is formed between the inner rotor pole shoe 4 and the inner motor 2, and between the outer rotor pole shoe 3 and the outer motor 1, the rotor assembly in the present application can be matched with the inner motor 2 alone, and can also be matched with the outer motor 1 alone, so that the dual-stator single-rotor permanent magnet synchronous motor provided in the present application can have three fixed output power modes.

When the working condition is light load, power output can be achieved only by supplying power to the inner motor 2; when the working condition is between light load and heavy load, power output can be achieved only by supplying power to the outer motor 1; when the working condition is heavy load, it is necessary to connect the inner motor 2 and the outer motor 1 in series and supply power to realize the joint action of the inner motor 2 and the outer motor 1 to achieve maximum power output to adapt to the heavy load condition.

Since the motor provided by the present application fully utilizes the internal space of the outer motor 1, it can improve the torque density and efficiency of the motor while ensuring that the volume remains unchanged. Moreover, through three different power outputs, it can not only better adapt to different working conditions, but also, when one of the inner motor 2 and the outer motor 1 fails, power can still be supplied for a certain period of time through the other structure, thereby improving the fault-tolerant operation capability of the motor to a certain extent.

As shown in FIG. 1 and FIG. 2 , the rotor assembly in the present application further includes a magnetic isolation ring 6 , and the magnetic isolation ring 6 is located between the outer rotor pole shoe 3 and the inner rotor pole shoe 4 .

The magnetic isolation ring 6 in the present application is made of aluminum material. By arranging the magnetic isolation ring 6 between the inner rotor pole shoe 4 and the outer rotor pole shoe 3, since the magnetic isolation ring 6 in the present application is non-magnetic, it is possible to achieve magnetic circuit decoupling between the inner motor 2 and the outer motor 1, thereby reducing to a certain extent the problem of the two magnetic fields of the inner motor 2 and the outer motor 1 influencing each other when the inner motor 2 and the outer motor 1 are running at the same time.

In order to further enhance the connection strength between the magnetic isolation ring 6 and the inner rotor pole shoe 4 and the outer rotor pole shoe 3, preferably, as shown in FIGS. 1-3 , in the present application, a plurality of first embedded portions 601 are formed on the side of the magnetic isolation ring 6 facing the outer rotor pole shoe 3, and the plurality of first embedded portions 601 are evenly distributed along the circumference of the magnetic isolation ring 6; a first matching portion 302 is formed at the position of the outer rotor pole shoe 3 corresponding to the first embedded portion 601, and the first matching portion 302 matches with the first embedded portion 601 to connect the outer rotor pole shoe 3 with the magnetic isolation ring 6.

In the present application, the first embedded portion 601 and the first matching portion 302 are arranged in a one-to-one correspondence, and during assembly, the first matching portion 302 formed on the side of the outer rotor pole shoe 3 facing the magnetic isolation ring 6 in the present application is embedded in the first embedded portion 601 formed by the magnetic isolation ring 6, thereby achieving a stable connection between the outer rotor pole shoe 3 and the magnetic isolation ring 6.

Since the rotor assembly will generate centrifugal force when it is in motion, the first mating portion 302 in the present application is a dovetail-shaped convex groove structure, and the first embedded portion 601 is a dovetail-shaped groove structure, so that the outer rotor pole shoe 3 can be clamped with the magnetic isolation ring 6, and when the rotor assembly rotates to generate centrifugal force, the structure provided by the present application can make the connection between the outer rotor pole shoe 3 and the magnetic isolation ring 6 tighter.

Further preferably, as shown in Figures 1 to 3, in the present application, a plurality of second embedded portions 602 are formed on the side of the magnetic isolation ring 6 facing the inner rotor pole shoe 4, and the plurality of second embedded portions 602 are evenly distributed along the circumference of the magnetic isolation ring 6; a second matching portion 402 is formed at the position of the inner rotor pole shoe 4 corresponding to the second embedded portion 602, and the second matching portion 402 cooperates with the second embedded portion 602 to connect the inner rotor pole shoe 4 with the magnetic isolation ring 6.

In the present application, the second embedded portion 602 and the second matching portion 402 are arranged in a one-to-one correspondence, and during assembly, the second matching portion 402 formed on the side of the inner rotor pole shoe 4 facing the magnetic isolation ring 6 in the present application is embedded in the second embedded portion 602 formed by the magnetic isolation ring 6, thereby achieving a stable connection between the inner rotor pole shoe 4 and the magnetic isolation ring 6.

Since the rotor assembly generates centrifugal force when it rotates, in the present application, the second matching portion 402 is formed into a dovetail-shaped convex groove structure, and the second embedded portion 602 is formed into a dovetail-shaped groove structure, so that the inner rotor pole shoe 4 and the magnetic isolation ring 6 can be clamped together, and when the rotor assembly rotates to generate centrifugal force, the structure provided by the present application can make the connection between the outer rotor pole shoe 3 and the magnetic isolation ring 6 tighter.

It should be supplemented here that, as shown in FIG. 2 , in the present application, the number of first embedded portions 601 and second embedded portions 602 is the same, and the axis of adjacent first embedded portions 601 is set at an angle to the axis of the second embedded portions 602 .

By arranging the axis of the first embedded portion 601 and the axis of the second embedded portion 602 at an angle, that is, staggering the first embedded portion 601 and the second embedded portion 602, the cogging torque of the motor can be weakened, thereby reducing the motor torque pulsation, improving the stability of the motor operation, and reducing the jitter problem under load to a certain extent.

Among them, as shown in Figure 1 and Figure 3, in the present application, a plurality of first air magnetic barriers 301 are formed on the outer rotor pole shoe 3, and the plurality of first air magnetic barriers 301 are symmetrically arranged along the axis of the outer rotor pole shoe 3; a plurality of second air magnetic barriers 401 are formed on the inner rotor pole shoe 4, and the plurality of second air magnetic barriers 401 are symmetrically arranged along the axis of the inner rotor pole shoe 4; the plurality of first air magnetic barriers 301 and the plurality of second air magnetic barriers 401 are both filled with resin material.

As shown in Figure 3, in the present application, the number of first air magnetic barriers 301 formed on the outer rotor pole shoe 3 is the same as the number of second air magnetic barriers 401 formed on the inner rotor pole shoe 4, and the first air magnetic barriers 301 on the outer rotor pole shoe 3 are symmetrically arranged along the axis of the outer rotor pole shoe 3, and the second air magnetic barriers 401 on the inner rotor pole shoe 4 are symmetrically arranged along the axis of the inner rotor pole shoe 4, thereby improving the salient pole ratio of the motor.

It can be understood that the above-mentioned salient pole ratio is the ratio between the motor q-axis inductance Lq and the motor d-axis inductance Ld. The first air magnetic barrier 301 formed on the outer rotor pole shoe 3 and the second air magnetic barrier 401 formed on the inner rotor pole shoe 4 can increase the ratio between Lq and Ld, thereby increasing the content of the magnetic resistance torque in the motor output torque, thereby improving the torque density of the motor.

Since the thermal conductivity of the air inside the first air magnetic barrier 301 and the second air magnetic barrier 401 is low, it is not conducive to the heat dissipation of the rotor assembly and easily leads to a high local temperature rise inside the rotor assembly. Therefore, preferably, in the present application, the first air magnetic barrier 301 and the second air magnetic barrier 401 are both filled with resin material, so as to improve the thermal conductivity of the first air magnetic barrier 301 and the second air magnetic barrier 401 to a certain extent and prevent the problem of high local temperature rise of the rotor assembly.

It should be noted here that in the present application, the outer rotor pole shoe 3 and the inner rotor pole shoe 4 are formed by stacking a plurality of silicon steel sheets in sequence, the first air magnetic barrier 301 and the second air magnetic barrier 401 are formed by cutting, and the ratio of the thickness of the first air magnetic barrier 301 to the thickness of the outer rotor pole shoe 3 and the ratio of the thickness of the second air magnetic barrier 401 to the thickness of the inner rotor pole shoe 4 are both 1:3.5.

It should be noted here that since the inner rotor pole shoe 4 and the outer rotor pole shoe 3 in the present application are both formed by stacking multiple silicon steel sheets, the thickness of the inner rotor pole shoe 4 and the thickness of the outer rotor pole shoe 3 in the present application refer to the thickness of the magnetic conductive layer of the silicon steel sheet.

Furthermore, as shown in FIG. 1 , in the present application, permanent magnets 5 are disposed between adjacent outer rotor pole shoes 3 and adjacent inner rotor pole shoes 4 .

Preferably, the permanent magnet 5 in the present application is made of neodymium iron boron material, and the permanent magnet 5 in the present application is magnetized along the tangential direction of the rotor assembly.

Furthermore, as shown in Figure 1, the outer motor 1 in the present application includes an outer stator core 101 and a first winding 102, and the inner motor 2 includes an inner stator core 201 and a second winding 202; the inner ring wall of the outer stator core 101 is formed with a plurality of first bearing grooves, and the plurality of first bearing grooves are evenly spaced along the circumference of the inner ring wall of the outer stator core 101, and the axis of the first bearing grooves extends along the radial direction of the outer stator core 101, and the two long sides of the first winding 102 are respectively arranged in two adjacent first bearing grooves; the outer ring wall of the inner stator core 201 is formed with a plurality of second bearing grooves, and the plurality of second bearing grooves are evenly spaced along the circumference of the outer ring wall of the inner stator core 201, and the axis of the second bearing grooves extends along the radial direction of the outer stator core 101, and the two long sides of the second winding 202 are respectively arranged in two different second bearing grooves.

The multiple first bearing grooves formed by the outer stator core 101 of the present application can stably carry the first winding 102, and the multiple second bearing grooves formed by the inner stator core 201 can stably carry the second winding 202. In addition, since the multiple first bearing grooves in the present application are evenly distributed along the circumference of the outer stator core 101 and the multiple second bearing grooves are evenly distributed along the circumference of the inner stator core 201, the relative rotation process of the rotor core can be made more stable and uniform, thereby improving the stability of the motor output.

It can be understood that in the present application, the first bearing groove is a rectangular groove structure, and the second bearing groove is approximately a rectangular groove structure. Therefore, it has three axes. The above-mentioned radially extending axes are the axes of the first bearing groove and the second bearing groove in the width direction, and the axes of the first bearing groove and the second bearing groove in the length direction both extend along the axial direction of the outer stator core 101 and the inner stator core 201.

It should be additionally explained here that, in the present application, the two long sides of the first winding 102 and the two long sides of the second winding 202 are both the two side coil sides of the winding.

Preferably, the first winding 102 in the present application is a formed winding, the second winding 202 is a scattered wire winding, and the open end of the second bearing slot in the present application is a closed structure, that is, a semi-closed slot structure, so that the tooth harmonic content can be reduced to a certain extent, and the low tooth harmonic content can further reduce the torque pulsation and harmonic loss of the motor. Since the formed winding cannot be embedded in the semi-closed slot structure, the first bearing slot in the present application needs to be used with a rectangular slot structure.

Secondly, the formed winding has the advantages of being strong and durable and convenient to insert the wire compared to the traditional scattered wire winding, and is therefore widely used in low-speed direct-drive motors. Since the outer motor 1 of the dual-stator single-rotor permanent magnet synchronous motor provided by the present application has a large diameter, the tooth width is relatively wide. Therefore, when concentrated winding is used, the distance between the left and right coil sides of each formed winding is relatively wide, so that it can be directly wound out using a winding machine.

Since the inner motor 2 is placed in the cavity of the outer motor 1, the outer diameter of the inner motor 2 is smaller and the tooth width is also smaller, which means that if a formed winding is used, the distance between the left and right coil sides of the formed winding is very narrow. The narrow distance between the left and right coil sides will severely limit the bending of the flat copper wire at the end of the formed winding, making it impossible to process such a formed winding. Therefore, the second winding 202 in the present application adopts a traditional loose wire winding, which can realize the assembly and forming of the overall motor.

It can be understood that the first winding 102 and the second winding 202 in the present application are both three-phase windings, the tail ends of phase A, phase B and phase C of the first winding 102 are X, Y, Z, and the tail ends of phase a, phase b and phase c of the second winding 202 are x, y, z.

Since the motor has torque pulsation during rotation, when the torque pulsation is large, the stability of the motor is poor, and the process of dragging the load is prone to jitter, which not only affects the stability of the motor speed, but also increases the energy consumption of the motor. Therefore, in order to suppress torque pulsation in this application, preferably, the first winding 102 is sequentially offline in the clockwise direction according to the offline sequence of A-Z-B-X-C-Y, and the second winding 202 is sequentially offline in the clockwise direction according to the offline sequence of a-z-b-x-c-y.

When the motor drives a heavy load, the first winding 102 of the outer motor 1 and the second winding 202 of the inner motor 2 are connected in series. At this time, the tail end of the A phase of the first winding 102 is X and is connected to the tail end of the a phase of the second winding 202 is x, so that the A phase of the first winding 102 and the a phase of the second winding 202 are connected in series. Similarly, the B phase of the first winding 102 and the b phase of the second winding 202 and the C phase of the first winding 102 and the c phase of the second winding 202 are connected in series. After the series connection, the tail ends of the three phases are connected in a star connection, and the three-phase electricity output by the inverter is connected to the A, B, and C phases respectively. At this time, the inner and outer motors 1 work simultaneously to drive the heavy load.

When the load torque is less than 1/4 of the rated torque, the tail ends x, y, and z of the three-phase winding of the second winding 202 are connected in a star connection, and the head ends a, b, and c are powered by an independent inverter, and the inner motor 2 works alone.

When the load torque is greater than 1/4 of the rated torque and less than 3/4 of the rated torque, the three-phase winding tail ends X, Y, and Z of the first winding 102 are connected in a star connection, the head ends A, B, and C are powered by an independent inverter, and the external motor 1 works alone.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. A dual-stator single-rotor permanent magnet synchronous motor, characterized in that it comprises an outer motor, a rotor assembly and an inner motor; The rotor assembly includes a plurality of outer rotor pole shoes and a plurality of inner rotor pole shoes, a cavity is formed inside the outer motor, the inner motor and the rotor assembly are both arranged in the cavity, and the rotor assembly is located between the inner motor and the outer motor; The plurality of outer rotor pole shoes are evenly arranged along the circumference of the outer motor, the plurality of inner rotor pole shoes are evenly arranged along the circumference of the inner motor, and gaps are formed between the outer rotor pole shoes and the outer motor, and between the inner rotor pole shoes and the inner motor; A plurality of first air magnetic barriers are formed on the outer rotor pole shoe, and the plurality of first air magnetic barriers are symmetrically arranged along the axis of the outer rotor pole shoe; A plurality of second air magnetic barriers are formed on the inner rotor pole shoe, and the plurality of second air magnetic barriers are symmetrically arranged along the axis of the inner rotor pole shoe; The first plurality of air magnetic barriers and the second plurality of air magnetic barriers are all filled with resin material; The first air magnetic barrier and the second air magnetic barrier are both formed by cutting. 2. The dual-stator single-rotor permanent magnet synchronous motor according to claim 1 is characterized in that the rotor assembly also includes a magnetic isolation ring, and the magnetic isolation ring is located between the outer rotor pole shoe and the inner rotor pole shoe. 3. The dual-stator single-rotor permanent magnet synchronous motor according to claim 2, characterized in that a plurality of first embedded portions are formed on one side of the magnetic isolation ring facing the outer rotor pole shoe, and the plurality of first embedded portions are evenly distributed along the circumference of the magnetic isolation ring; A first matching portion is formed at a position of the outer rotor pole shoe corresponding to the first embedded portion, and the first matching portion matches with the first embedded portion to connect the outer rotor pole shoe to the magnetic isolation ring. 4. The dual-stator single-rotor permanent magnet synchronous motor according to claim 3, characterized in that a plurality of second embedded portions are formed on one side of the magnetic isolation ring facing the inner rotor pole shoe, and the plurality of second embedded portions are evenly distributed along the circumference of the magnetic isolation ring; A second matching portion is formed at a position of the inner rotor pole shoe corresponding to the second embedded portion, and the second matching portion matches with the second embedded portion to connect the inner rotor pole shoe to the magnetic isolation ring. 5. The dual-stator single-rotor permanent magnet synchronous motor according to claim 4 is characterized in that the first matching portion and the second matching portion are both dovetail convex groove structures, and the first embedded portion and the second embedded portion are both dovetail groove structures. 6 . The dual-stator single-rotor permanent magnet synchronous motor according to claim 4 , characterized in that the number of the first embedded parts and the second embedded parts are the same, and the axes of adjacent first embedded parts are arranged at an angle to the axes of adjacent second embedded parts. 7. The dual-stator single-rotor permanent magnet synchronous motor according to claim 1 is characterized in that the outer rotor pole shoe and the inner rotor pole shoe are both formed by stacking a plurality of silicon steel sheets in sequence, and the ratio of the thickness of the first air magnetic barrier to the thickness of the outer rotor pole shoe and the ratio of the thickness of the second air magnetic barrier to the thickness of the inner rotor pole shoe are both 1:3.5. 8. The dual-stator single-rotor permanent magnet synchronous motor according to claim 1, characterized in that permanent magnets are provided between adjacent outer rotor pole shoes and adjacent inner rotor pole shoes. 9. The dual-stator single-rotor permanent magnet synchronous motor according to claim 1, characterized in that the outer motor comprises an outer stator core and a first winding, and the inner motor comprises an inner stator core and a second winding; The inner ring wall surface of the outer stator core is formed with a plurality of first bearing grooves, the plurality of first bearing grooves are evenly spaced along the circumference of the inner ring wall surface of the outer stator core, and the axes of the first bearing grooves extend along the radial direction of the outer stator core, and the two long sides of the first winding are respectively arranged in two adjacent first bearing grooves; The outer ring wall surface of the inner stator core is formed with a plurality of second bearing grooves, which are evenly spaced along the circumference of the outer ring wall surface of the inner stator core, and the axes of the second bearing grooves extend along the radial direction of the inner stator core, and the two long sides of the second winding are respectively arranged in two different second bearing grooves.